Cichlid "Nannies" and "Cuckoo" Catfish
A cuckoo catfish fry pokes its head out from the nanny cichlid's mouth.
Photo: Nova Science Now
Cichlids are a genus of mouthbrooding fish - that is, after laying her eggs, the mother gathers them in her mouth to hatch and continues to keep them safe there as they grow large and strong enough to avoid predators on their own. In Lake Tanganyika, the carefree "cuckoo" catfish Synodontis multipunctata
, compensates for its own poor parenting skills by taking advantage of these cichlids' nurturing nature. It does this (much like its avian namesake) by stealing and eating the cichlid eggs immediately after they have been laid, then leaving its own eggs behind as it swims carelessly away. The cichlids capture the catfish eggs in their mouths thinking they are their own, and harbor them there as the eggs hatch and the fry mature. The catfish young gobble up any remaining cichlid young as the cichlid nanny continues to care for them and protect them from any other predators.
Here's a video from National Geographic showing just how cuckoo catfish con cichlid fish.
The Gray Whale's Guide to Postpartum Dieting
A gray whale calf nurses from its lean mother.
To protect their young from orcas and other dangerous predators, pregnant Pacific gray whales migrate from the plankton-rich Arctic waters of their home thousands of miles until they reach relatively nutrient-poor tropical lagoons off of the coast of Mexico, where they then give birth. In the safety of the nursery, their newborns take time to feed and grow on their mothers' incredibly rich milk (53 percent fat!), building a layer of insulating blubber before they head back to the icy Arctic. The mother whales go hungry for months while still needing to produce high-calorie milk for their babies. During this time they may lose as much as 8 tons of weight.
Octo-moms with a Serious Case of the Munchies
A Pallidus octopus guards her eggs.
Depending on her species, a mother octopus will lay anywhere between 50,000 and 200,000 eggs, carefully group the eggs in the optimal brooding arrangement, and then spend the next couple of months caring for the eggs. This involves protecting them against predators and even pushing water currents toward them so the eggs are sufficiently oxygenated. During this entire period, she will not hunt and has been known to ingest her own arms for sustenance; an act known as "autophagy". As the eggs start hatching, she will leave her lair too weak to defend herself from predators and as a result, most octopus mothers die shortly afterward. While it was once thought that octopuses were making the ultimate sacrifice for their young through this desperate craving for food, it has since been discovered that the behavior is a result of a nueurological viral or bacterial infection contracted as a result of lowered activity and biological aging during brooding.
For an interesting scientific overview of autophagy in octopuses, take a look at this article.
Dolphins: It Takes a Village
A pair of Indo-Pacific bottlenose dolphins and their young form an impromptu play group.
Photo: Australian Geographic
Dolphins of all species are social and intelligent animals. Just like humans; they live in extended families, maintain long-term friendships, and learn from what they are shown and taught. This is an important trait, since young dolphins are not born with the skills necessary to fend for themselves. In fact, the mortality rate for dolphin calves is 50% in the first year.
A mother dolphin will call upon her female friends to help her out during calving, and then to protect her and her baby from shark attacks and aggressive males while she is teaching her child survival skills. The calf is born with the ability to mimic and mirror everything its mother does, becoming Mom's shadow, imitating her every move, pose, posture, and action, including how to find food and even use tools.
Find out more of how successful dolphin mothers get help from their friends
For a demonstration of dolphin parenting, watch this video
To learn more about cultural transmission of tool use by dolphins, read this article.
Killer Whales: You're Never Too Old to Be "Mama's Boy"
Whales of all species , like marine mammals in general, are known for their attentive parenting, extending even beyond the first year of their offspring's life. However, orcas in particular often continue to care for their young well into their adult life, helping their adult offspring survive and reproduce. When sons mate, the offspring go with their mother to be cared for by females in her group while the sons remain with the matriarch; when daughters reproduce, the offspring stay in the matriarch's group under the daughter's care. However, in order to have the best chance of increasing transmission of their genes with the least burden, mothers focus their efforts on their sons.
Scientists have also found that orca (and pilot whale) mothers achieve menopause relatively early in life, and those that are menopausal are likely to be more successful in raising their young. One theory is that giving birth to calves and then losing the ability to reproduce helps the mother to focus on bringing up her offspring without wasting time and energy on further pregnancies. Scientists found that the oldest mothers may also be the best mothers. Older females may be more successful in raising young because of maternal experience, or they may allocate more effort to their offspring relative to younger females.
Read here how Older Killer Whales Make The Best Mothers
Find out how Long Menopause Allows Killer Whales to Care for Adult Sons.